Antioxidant properties and Flavonoids-Phenolic content of citrullus colocynthis (L.) schrad growing in Khuzestan, Iran

Free radicals cause several human diseases. Antioxidants decrease the risk of cardiovascular diseases and heart attack, and prevent the development of cancers through neutralization of free radicals. This study set out to determine the antioxidative properties of Citrullus colocynthis growing in Khuzestan. This plant is traditionally used for the treatment of type II diabetes.
In this study, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and beta-carotene linoleic acid assays were used for the evaluation of antioxidative properties. In addition, the measurement of flavonoids and phenolic compounds was done based on the Gallic acid and quercetin reagents.
In the DPPH assay, the maximum and minimum scavenging activity of free radicals were found in the extractions of stem (IC50=12.4μg/ml) and leaves (IC50=5.46 μg/ml), respectively. With respect to the beta-carotene linoleic assay, the maximum and minimum antioxidative activities were observed in the extractions of leaves (79.78%) and fruits (47.08%), respectively. Moreover, the maximum content of flavonoids and phenolic compound were 22.15μg/ml in stem, and 4.09μg/ml in fruit.
The methanol extracts from different organs of citrullus colocynthis (C. colocynthis) showed antioxidative activities at different levels. Therefore, they can be used as antioxidants in food industries and adjuvant treatments.